Lack of administrator control over security vulnerability in MELSEC-F series FX3U-ENET…
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA.
Summary
Lack of administrator control over security vulnerability in MELSEC-F series FX3U-ENET Firmware version 1.14 and prior, FX3U-ENET-L Firmware version 1.14 and prior and FX3U-ENET-P502 Firmware version 1.14 and prior allows a remote unauthenticated attacker to cause a denial-of-service (DoS) condition in communication function of the product or other unspecified effects by sending specially crafted packets to an unnecessary opening of TCP port. Control by MELSEC-F series PLC is not affected by this vulnerability, but system reset is required for recovery.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | MELSEC-F series FX3U-ENET; MELSEC-F series FX3U-ENET-L; MELSEC-F series FX3U-ENET-P502 | Firmware version 1.14 and prior | — | No fix listed | CNA |
- MELSEC-F series FX3U-ENET; MELSEC-F series FX3U-ENET-L; MELSEC-F series FX3U-ENET-P502 Vendor— Affected Firmware version 1.14 and prior Fixed in — No fix listed CNA
CPE configurations NVD · 6
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:mitsubishielectric:fx3u-enet_firmware:*:*:*:*:*:*:*:* | up to 1.14 | Vulnerable | Mitsubishi Electric Europe B.V. |
| cpe:2.3:h:mitsubishielectric:fx3u-enet:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Mitsubishi Electric Europe B.V. |
| cpe:2.3:o:mitsubishielectric:fx3u-enet-l_firmware:*:*:*:*:*:*:*:* | up to 1.14 | Vulnerable | Mitsubishi Electric Europe B.V. |
| cpe:2.3:h:mitsubishielectric:fx3u-enet-l:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Mitsubishi Electric Europe B.V. |
| cpe:2.3:o:mitsubishielectric:fx3u-enet-p502_firmware:*:*:*:*:*:*:*:* | up to 1.14 | Vulnerable | Mitsubishi Electric Europe B.V. |
| cpe:2.3:h:mitsubishielectric:fx3u-enet-p502:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Mitsubishi Electric Europe B.V. |
- cpe:2.3:o:mitsubishielectric:fx3u-enet_firmware:*:*:*:*:*:*:*:* Versions up to 1.14 Vulnerable ·Mitsubishi Electric Europe B.V.
- cpe:2.3:h:mitsubishielectric:fx3u-enet:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Mitsubishi Electric Europe B.V.
- cpe:2.3:o:mitsubishielectric:fx3u-enet-l_firmware:*:*:*:*:*:*:*:* Versions up to 1.14 Vulnerable ·Mitsubishi Electric Europe B.V.
- cpe:2.3:h:mitsubishielectric:fx3u-enet-l:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Mitsubishi Electric Europe B.V.
- cpe:2.3:o:mitsubishielectric:fx3u-enet-p502_firmware:*:*:*:*:*:*:*:* Versions up to 1.14 Vulnerable ·Mitsubishi Electric Europe B.V.
- cpe:2.3:h:mitsubishielectric:fx3u-enet-p502:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Mitsubishi Electric Europe B.V.
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2021-20612
- 2026-10-03 Alias added: GHSA-v6rf-w7jv-9fmc
- 2026-11-07 EPSS moved to the 90th–95th percentile
References
More Mitsubishi Electric Europe B.V. Fx3u-enet-l Firmware vulnerabilities
- TI-2023-04208 Information Disclosure, Information Tampering and Authentication Bypass Vulnerability in MELSEC-F Series main module CVSS 3.1CRITICAL 9.1
- TI-2020-12755 Mitsubishi Electric Multiple Products CVSS 3.1CRITICAL 9.8
- TI-2021-03842 Improper initialization vulnerability in MELSEC-F series FX3U-ENET Firmware version 1.16… CVSS 3.1HIGH 7.5
- TI-2021-03829 NULL pointer dereference in MELSEC-F Series FX3U-ENET; FX3U-ENET-L; FX3U-ENET-P502 CVSS 3.1HIGH 7.5
Sources
- CVE-2021-20612 · CVE Program
- CVE-2021-20612 · NVD
- FIRST EPSS
- GHSA-v6rf-w7jv-9fmc · GitHub Advisory Database · CC BY 4.0
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